Fix missing global. Update git hooks.

CHANGES.md

@@ -8,6 +8,8 @@ so you won't need to look at here very often.
 Here are a list of things that were changed, starting from an early version.
 TensorFlow itself also changed APIs before 1.0 and those are not listed here.
 
++ [2017/08/02](https://github.com/ppwwyyxx/tensorpack/commit/875f4d7dbb5675f54eae5675fa3a0948309a8465).
+	`Trainer.get_predictor` now takes GPU id. And `Trainer.get_predictors` was deprecated.
 + 2017/06/07. Now the library explicitly depends on msgpack-numpy>=0.3.9. The serialization protocol
 	becomes incompatible if you've been using <0.3.9.
 + [2017/05/06](https://github.com/ppwwyyxx/tensorpack/commit/0774ec66e66075486f6a36aba63cc2a151b9fec8).

examples/A3C-Gym/train-atari.py

@@ -208,6 +208,7 @@ class MySimulatorMaster(SimulatorMaster, Callback):
 
 def get_config():
     nr_gpu = get_nr_gpu()
+    global PREDICTOR_THREAD
     if nr_gpu > 0:
         if nr_gpu > 1:
             # use half gpus for inference

tests/dev/git-hooks/pre-commit

@@ -5,8 +5,9 @@ cd examples
 GIT_ARG="--git-dir ../.git --work-tree .."
 
 # find out modified python files, so that we ignored unstaged files
-MOD=$(git $GIT_ARG status -s | grep -E '\.py$'  | grep -E '^ *M|^ *A ' | cut -c 4-)
-# git $GIT_ARG status -s | grep -E '\.py$'
+# exclude ../docs
+MOD=$(git $GIT_ARG status -s | grep -E '\.py$'  \
+	| grep -E '^\b+M\b+' | cut -c 4- | grep -v '../docs')
 if [[ -n $MOD ]]; then
 	flake8 $MOD
 fi